The present invention relates to an improved moving method using a collapsible dolly system which can be for example used for assistance in moving a loaded stair climber around a horizontal stair landing, particularly one which is in tight quarters, the load bearing platform of the dolly being changeable from horizontal to inclined dispositions.
Powered stair climbing, load carrying tractors per se are, of course, old in the art as seen, for example, in U.S. Pat. No. 3,512,658, issued May 19, 1970 to a Mr. Verle M. Harlan. Indeed, for illustrative purposes only, the present invention will be described as applied to and for use with basic "Harlan" tractor similar to the embodiment of FIG. 4 of the Harlan patent; although, of course, the present invention is equally applicable to all types of power operated, load carrying, stair climbing devices as well as to other kinds of moving systems besides stair climbing ones.
Although these stair climbing devices are well known in the prior art, their use has left a lot to be desired, particularly when the load to be carried was very heavy, bulky and difficult to handle.
A very difficult problem that has been encountered with prior art stair climbing devices was the transferring of the loaded stair climber from one flight of stairs, across a landing and onto a second flight of stairs. Herein problems arose because of the tight quarters found on many stair landings wherein mere inches of clearance are very critical.
Thus, the prior art enabled movers to move the heavy machinery up a flight of stairs with ease but, upon reaching the landing, were still faced with the tugging and pushing and jolting of the loaded stair climber in order to manipulate it around the landing and up the next flight of stairs. This prior art method of transgressing the landing has made the advantage of the stair climber usually ineffective with regards to labor savings, in that three or more laborers would still be needed to manipulate the loaded stair climber on the landing. Even then, there would also be the sustained shock to the load during the manual handling thereof which may have been the very problem the stair climber was used to avoid.
A basic object of the present invention is inter alia to overcome this prior art problem found in the moving of heavy, bulky loads up flights of stairs in a relatively simple, straight forward and reliable manner; and to solve this prior art problem without the need for any additional complex or particularly sophisticated devices, allowing the use of the present invention by the relatively unskilled working personnel used in the moving industry.
The present invention achieves this goal by providing a relatively simple collapsible dolly system wherein the total horizontal, longitudinal dimension of the overall loaded moving system is minimized in tight quarters by the use of a collapsible dolly having both inclined and horizontal positions.